The surge in Omicron has forced American emergency doctor Morgan Eutermoser into medical decisions she has never faced before during the pandemic.
There are too many COVID patients in the waiting room, not enough doctors and nurses to treat them and not enough beds to provide the care she's been trained to give.
"You have this feeling in the back of your head, what's going on with the patients who have already been admitted to the hospital and how are we going to see these patients, how are we going meet the expectations of our patients?"
These days, as she walks into the emergency room at Denver Health, the hospital where she works, Dr Eutermoser is confronted by a waiting room with at least 60 patients.
Before the pandemic, there would have been about 10.
"We're moving into trying to figure out places where we can keep patients, observe them and not necessarily admit them," she told the ABC News Daily podcast.
"We're definitely at capacity."
US hospitals barely coping through Omicron wave
On the other side of the country, in Boston, emergency physician at the Brigham and Women's Hospital, Dr Jeremy Faust, described the difficult process of "real-time triaging" where patients are sent home earlier than hoped.
"If you are really, really full, you might discharge a couple of patients who you don't feel great about sending home," he said.
"But you probably know enough to know that if anything bad happens, they can come back just in time to get the care they need.
"You would be only admitting or hospitalising patients who really appear very, very sick."
Dr Faust, who also runs a website to track the capacity of all American hospitals, explained that many US facilities are operating at capacity because of the Omicron surge but are finding ways to stay operating.
But for the first time during the pandemic, Omicron had threatened to tip hospitals in the US over the edge, he said.
"At some point, if patients are fighting for resources, you end up with these horror situations — which we really have managed to avoid so far but has happened in some places around the world," he said.
"We saw [it] in Italy, where people don't have enough ventilators to offer them to the patients who needed them."
In the US, hospitalisation from COVID-19 is starting to decline as the Omicron peak is reached, but there are still around 150,000 COVID patients in hospital across the country every day, more than at any other point during the pandemic.
According to Dr Faust's research, almost a thousand US counties have hospitals either forecast to exceed their patient capacity or that already have.
His tracking shows some regions are worse than others, particularly in areas that have low vaccination rates.
He noted that even when vaccination rates are high, like in Boston where he works, there are still concerns.
"The one I keep on seeing over and over again is pregnant women who are not vaccinated because they were afraid that the vaccine would harm them or their future babies," he said
"It's a real problem because pregnant women have had terrible outcomes from coronavirus.
"There's something about that combination, which apparently really increases the risk of maternal disease, morbidity, mortality and now we know, stillbirths as well."
Treating the unvaccinated
In Denver, Dr Eutermoser also said treating the unvaccinated was a tragic and frustrating experience.
She recounted the case of an unvaccinated 50-year-old man who died after being admitted to the hospital with a 30 per cent oxygen level.
Dr Eutermoser said the patient's wife, not understanding the severity of the disease, asked her: "When can he go home? Can we go home today?"
She said the mistaken belief that COVID did not cause serious illness was common among the unvaccinated and their families.
"There's the significant misperception of what people think it [COVID-19] is," she explained.
In another case, a 30-year-old obese man asked to be vaccinated after being admitted to the hospital.
"I'm like, 'Well, I don't think you need the vaccine now because you have COVID,' and he was like, 'Well, is there anything else you can do?'"
She said she told the patient that the hospital would do everything they could for him.
"He ended up dying on day four," she said.
While her hospital has managed to cope with the number of admissions during the Omicron wave, it has come at a huge personal toll.
"It's getting really tough, I have many friends who are going part-time or looking at other things to do in life because it's really, really hard."
